Veterinarni Medicina, 55, 2010 (11): 561–565 Case Report

Guttural pouch mycosis in a donkey (Equus asinus): a case report

F. Laus, E. Paggi, M. Cerquetella, D. Spaziante, A. Spaterna, B. Tesei

School of Veterinary Medical Sciences, University of Camerino, Camerino, Italy

ABSTRACT: Guttural pouch mycosis is an emergency disease of the upper respiratory tract in equine species. In the present report a case of guttural pouch mycosis in a female, seven year-old pregnant donkey is described. A serious dyspnea which necessitated tracheotomy and preceding epistaxis was the most important clinical fea- ture of guttural pouch mycosis in the donkey. A full and rapid effectiveness of the topical therapy, the protocol for which is described, is the main distinguishing feature with regard to treatment. In the Authors’ knowledge a detailed description of clinical features, treatment and follow up of guttural pouch mycosis in a donkey is not available in the scientific literature. The anatomical and physiological peculiarity of donkeys could explain some of the differences with horses in clinical presentation and therapeutic management.

Keywords: donkey; guttural pouches; respiratory disease

Guttural pouch mycosis (GPM) is an infrequent bolization techniques are the most frequently used disease of horses reported to be fatal in 50% of cases (Hardy and Leveile, 2003). Conversely, topical and (Cook, 1968; Caron et al., 1987). systemic medical treatment are not considered to Fungal plaques, usually located on the roof of be efficacious (Aisworth and Hackett, 2004). the medial compartment and less frequently on the To the Authors’ knowledge a detailed description dorsolateral wall of the lateral compartment, repre- of clinical features, treatment and follow up of gut- sent the main features of the disease; plaques have tural pouch mycosis in a donkey is not available in a strong association with underlying structures, the scientific literature. usually the internal carotid, external carotid and In the present report we describe a case of GPM maxillary artery (Lane, 1989), but can also involve in a female, seven year-old donkey. stylohyoid bone and adjacent important nerves. Pathogenesis is not completely understood and it is unclear whether the dilation of vascular struc- Case description tures often observed endoscopically is a predis- posing cause or a consequence of fungal infection A seven year-old, pregnant female, Martina Franca (Aspergillus spp.) (Colles and Cook, 1983). Affected breed donkey was conducted to our Hospital be- animals may exhibit spontaneous epistaxis, dys- cause of hyperacute dispnoea followed by profuse phagia, nasal discharge, facial paralysis, Horner’s epistaxis (Figure 1). syndrome and mycotic encephalitis (Hardy and The patient showed severe inspiratory distress Leveile, 2003; Aisworth and Hackett, 2004). and made loud inspiratory noises; an emergency Endoscopical examination can reveal dorsal dis- tracheotomy was carried out to avoid a forthcom- placement of the , laryngeal hemiplegia ing asphyxial crisis. Immediately after tracheotomy or pharyngeal paralysis. Diagnosis is confirmed by the donkey became quiet and a few minutes sub- detection of micotic plaques during endoscopy of sequently bleeding also subsided, allowing clini- guttural pouches. Surgery is usually recommended; cal and endoscopical evaluation. The animal had ballon-tipped and transtarterial coil em- a poor body condition and appeared depressed.

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and dihydrostreptomycin (11 mg/kg i.m. BID) was started, associated with ranitidine (6.6 mg/kg p.o. TID) to prevent gastric ulcerations. Twenty-four hours after hospitalization a second endoscopy was carried out. The dorsal wall of the was still occluding the larynx and pre- venting its visualization but no blood clots were present. The right guttural pouch was normal while the mucosal lining of the left guttural pouch was congest and edematous (indicating inflammation) and a viscous grey material covered the stylohyoid bone, part of the medial compartment and the me- dian septum (Figure 3). A yellowish-black, pointed, fungal plaque was located in the lateral compart- Figure 1. Bilateral epistaxis ment, on the wall of the maxillary artery (Figure 4). The plaque was about 1 cm in diameter and below Mucus membranes were pale and the pupil of the it there was a focal aneurysmal dilatation of the ar- left eye was miotic. At endoscopy a unilateral he- terial wall. A sample of guttural pouch lavage fluid morrhage (blood clot) was evident from the left was obtained by instillation and aspiration of 10 ml guttural pouch opening but the endoscope was not of sterile saline solution and used for cytological introduced into the pouch to avoid the dislocation and bacteriological examinations. Endoscopy also of the clot and a new haemorrhage (Figure 2). The showed the presence of food in the pharynx and dorsal wall of the pharynx was ventrally displaced trachea. meaning epiglottis and arytenoids cartilages were Cytological examination revealed the presence of not visible. Rectal examination and ultrasonogra- some coccaceous that at microbiological phy showed the foal to be alive. examination were indentified as Streptococcus equi Haemocrome showed marked anaemia (RBC = subsp. zooepidemicus. 6 3.2 × 10 ; HGB 6.4 g/dl) and a decreased hematocrit The same day the donkey showed a marked (18.5%) (Zinkl et al., 1990). , causing nasal food discharge but only The donkey was hospitalized and antibiotic ther- occasional coughing. Nevertheless, crackles and apy with penicillin procaine (9000 IU/kg i.m. SID) wheezes were present at pulmonary ausculta-

Figure 3. Fungal plaque on maxillary artery and stylohy- Figure 2. Blood clots from left guttural pouch opening oid bone

562 Veterinarni Medicina, 55, 2010 (11): 561–565 Case Report

Figure 4. Detail of the mycotic plaque on the maxillary artery

tion (). The owners did not application was repeated 48 hours later and for a consent to surgery for financial reasons and the further four times every 72 hours making a total decision was undertaken to implement topical an- of six applications. At the time of the fourth treat- tifungal therapy. ment the inflammation was absent and the plaque On the following day (three days from the first started to become smaller and lighter in colour. At haemorrhage) a new endoscopy was performed and the fifth treatment the erosion triggered by fungal 15 ml of a 2% miconazole gel-emulsion was applied infection caused a fistula in the median septum topically on the entire left guttural pouch mucosa (Figure 5) but without fungal involvement in the through an indwelling catheter passed in the ac- controlateral pouch. At the last treatment no fun- cessory channel of the scope. On the next day the gal lesions were visible but the aneurysm was still donkey had a new episode of haemorrhage and, in a evident (Figure 6). few hours, aborted and developed a light laminitis Dysphagia improved gradually and had complete- treated with the appropriate hoof care, corrective ly disappeared after 30 days, as did anisocoria and shoes and antiinflammatory therapy. Despite the laminitis. A tracheotomy tube was kept inside until new haemorrhage, blood analysis did not show day six (2nd treatment), when the endoscopic pha- further worsening of the anaemia. Miconazole ryngeal appearance did not show upper airway ob-

Figure 5. Fistula on the median septum observed from the left guttural pouch

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Figure 6. Aneurismal dilatation of the max- illary artery after recovery of the plaque

struction. After thirty-two days of hospitalization of the pharynx as a result of both neurological and the animal was discharged from the Hospital. mechanical alterations, exacerbating the tendency to collapse. Since the history reported that epistaxis started a few hours after the dyspnea, the latter DISCUSSION AND CONCLUSIONS could be an early symptom of GPM in donkeys. The donkey reported on in the present paper Despite some personal communications regard- also presented neurological dysfunctions causing ing guttural pouch mycosis in donkeys, to our dysphagia and ipsilateral meiosis arising from dam- knowledge this is the first case report describing age to the nerves in contact with guttural pouches the progression of the diseases in this species. ( IX, X, XI XII), similarly to what Donkeys are normally treated like small horses happens in horses. Also, the erosion of the median but they have many peculiarities in incidence, septum, rarely occurring in horses, has been found presentation and treatment of diseases. Such dif- to be a possible complication in donkeys. Similar ferences have been highlighted also in our case; to what happens in the horse, also in our patient for example, when the patient presented only poor it was not possible to determine if the aneurism respiratory symptoms after developing aspiration was a consequence of, or a predisposing factor for pneumonia (little coughing and no fever). plaque formation. Some peculiar clinical features of GPM in don- Lindsay and Clayton (1986) found that to pass an keys could be due to their important anatomical endoscope through the pharyngeal opening of gut- differences with horses: in the donkey the na- tural pouches is more difficult in Spanish donkeys sopharynx is more constricted in its middle part than in horses. In our case there were no differences and more flared dorso-ventrally than in the horse in the technique between Martina Franca donkeys and, because of the shorter aryepiglottic folds, and horses. the epiglottis is normally closer to the arytenoids Topical treatment, normally considered inef- cartilages (Lindsay and Clayton, 1986; Fores et al., fective in horses (Ainsworth and Hackett, 2004), 2001). Furthermore, Delvaux et al. (2001) observed worked very well in our case. Topical treatment a partial collapse of the pharynx in 43% of normal with enilconazole alone has been shown to be ef- donkeys endoscopically examined. These differ- fective in resolving dysphagia only in one single ences could explain the severe dyspnea observed horse. The treatment schedule we used consisted in the donkey at the first visit (normally not found in the endoscopical application of miconazole a in horses) when inflammation and bleeding in the total of six times, every 72 hours. Such a protocol guttural pouch could have caused the narrowing is very short and less intensive that those suggested

564 Veterinarni Medicina, 55, 2010 (11): 561–565 Case Report for horses, where daily administration for longer Colles CM, Cook WR (1983): Carotid and cerebral angi- periods (more than 30 days) is normally required. ography in the horse. Veterinary Record 113, 483–489. Although we cannot make any conclusions about Cook WR (1968): The clinical features of guttural pouch the aetiology, the rapid and complete response of mycosis in the horse. Veterinary Record 83, 336–345. the donkey to the topical therapy could be due to Delvaux V, Kirschvink N, Amory H, Busoni V, Art T, the involvement of a more miconazole-sensitive Lekeux P (2001): Spécificités de la function cardiores- fungus. Nevertheless, the gel-emulsion formulation piratoire de l’âne (Equus asinus). Pratique Veterinaire of the drug may also have contributed to a better Equine 33, 21–28. http://hdl.handle.net/2268/10351 distribution of the drug on the mucosal surface of Fores T, Lopes J, Rodriguez A, Harran R (2001): Endos- the pouch and, therefore, a more effective action. copy of the upper airway and the proximal digestive More clinical cases will be necessary to better tract in the donkey (Equus asinus). Journal of Equine assess what are the differences in clinical manifesta- Veterinary Sciences 21, 17–20. tion and therapeutic management of guttural pouch Hardy J, Leveile R (2003): Diseases of the guttural mycoses between horses and donkeys. pouches. Veterinary Clinic of North America-Equine Practice 19, 123–158. Lane JG (1989): The management of guttural pouch REFERENCES mycosis in the horse. Equine Veterinary Journal 21, 321–324. Aisworth DM, Hackett RP (2004): Disorders of the res- Lindsay F, Clayton H (1986): An anatomical and endo- piratory system. In: Reed SM, Bayly WM, Sellon DC scopic study of the nasopharynx and larynx of the don- (eds.): Equine Internal Medicine. 2nd ed. Saunders, key (Equus asinus). Journal of Anatomy 144, 123–132. Missouri. 289–353. Zinkl JG, Mae D, Guzman Merida P, Farver TB, Humble Caron JP, Fretz PB, Bailey JV, Barber SM, Hurtig MB JA (1990): Reference ranges and the influence of age (1987): Balloon-tipped catheter arterial occlusion for and sex on hematologic and serum biochemical values prevention of hemorrhage caused by guttural pouch in donkeys (Equus asinus). American Journal of Vet- mycosis: 13 cases (1982–1985). Journal of American erinary Research 51, 408–413. Veterinary Medical Association 191, 345–349. Received: 2010–03–11 Accepted after corrections: 2010–10–21

Corresponding Author: Dr. Fulvio Laus, University of Camerino, School of Veterinary Medical Sciences, Via Circonvallazione, 93/95 – 62024 Matelica (MC), Italy Tel. +39 0737 403403, E-mail: [email protected]

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